We don't know much about Syracuse politics, but in that case, it is more likely this was done by soldiers. Syracuse garrison would have been at least a thousand

We don't know much about Syracuse politics, but in that case, it is more likely this was done by soldiers. Syracuse garrison would have been at least a thousand troops and more probably several thousands. While waiting for the ships to land, it sounds like a good idea to try and sync them to try make the ships catch fire.